Sunday, 5 March 2017

Cwm Colliery

Yesterday afternoon Karen Wilkinson and I spent a few hours looking at the bryophytes of Cwm Colliery, near Beddau. It's a big place and we only really scratched the surface, but we managed to add quite a few species for the under-recorded tetrads ST08S and ST08T.

Liam Olds has done a lot of invert surveys at this site, and had mentioned the presence of tufaceous springs - something I'd not seen on colliery spoil. We looked at a couple of these on the western side of the tip - they certainly look odd but we failed to find any unusual bryophyte species: only Didymodon tophaceus, Aneura pinguis, Cratoneuron filicinum and Bryum pseudotriquetrum were recorded on the tufa.

Elsewhere, we found a couple of patches of what looks like it might be Lophocolea semiteres growing on spoil under young birch - photos below. I'm not absolutely sure it's not L. heterophylla - some of the leaf tips are retuse but most are entire, and none are very notched. Photos below.

Most of the spoil was fairly species-poor but we did find small patches of Calliergonella lindbergii (photo below), Archidium alternifolium, Campyliadelphus chrysophyllus and Weissia brachycarpa var obliqua. The young willow and birch woodland was quite rich, with Rhytidiadelphus triquetrus and a good range of epiphytes.

There are large areas in the north and east of the site left to explore, so further visits are needed.


  1. L.semiteres is an interesting addition to colliery spoil in the county, as well as being only the second vcr - good spot! I've plenty more sites to add, but the total list of bryos recorded directly on colliery spoil in West Glamorgan (n=8) currently stands at 128 (avge 44 spp) with Calliergonella cuspidata and Archidium alternifolium being the two most frequent (pretty much constant) species. I'll post the list when it's more complete.

  2. Thanks Barry - I'm still not 100% sure it's semiteres but Karen's sample is similar to mine, so I think so. Will try and post a microscope pic tomorrow...

  3. I`ve noted tufaceous springs on Carms colliery sites too, but also be aware of saline conditions developing at other locations when salts are either leached out of the rocks or whatever. Species such as sea club-rush and saltmarsh soldier-flies (eg Stratiomys singularior) also be aware of saltmarsh bryo potential.